1. Field of the Invention
This invention relates to actuators for moving a member and more particularly to an improved control system for providing a controlled force during the movement of the member for reducing the possibility of damage or injury to an unintended object or person in the path of the member while producing a positive force at the termination of movement for insuring proper positioning of the member.
2. Background of the Invention
The increased competition in manufacturing business has encouraged the increased use of automation in an assembly process. As automation has become faster and more efficient, there has been a corresponding reduction in direct human observation of the manufacturing process. As a result, there exists an increased need for providing automatic machines that are capable of accommodating for unusual situation such as an unintended object in the path of the moving automatic machine.
In most automatic machines, a tool is moved in proximity to a workpiece for enabling the tool to operate upon the workpiece. In some instances, the tool is moved relative to the workpiece whereas in other situations, the workpiece is moved relative to the tool. Typically, the workpiece is aligned relative to the tool prior to the movement of the tool. When the tool is properly aligned relative to the workpiece, the tool is moved into contact with the workpiece and the tool performs the operation on the workpiece. After the operation is performed on the workpiece, the workpiece is moved to another position for further operations.
Most automated machines are incapable of accommodating for unusual situation such as an unintended object in the path of the moving automatic machine. One unusual situation includes the unintended object being a workpiece being misaligned relative to the tool. If the workpiece is misaligned relative to the tool, the tool may cause damage to either the workpiece or the tool thus causing a loss of product or tooling. In addition, the automated process must be terminated in order to repair the damaged workpiece or the tool.
Another and more unpleasant unusual situation includes the unintended object being a worker being caught between the workpiece and the tool. A worker may be severely injured if accidentally caught by the movement of the tool relative to the workpiece. Such an injury is extremely costly to an automated process.
Therefore, it is an object of the present invention to provide an improved actuator for moving a member such as a tool or a workpiece with a controlled force for reducing the possibility of damage or injury to an unintended object or person in the path of the member.
Another object of this invention is to provide an improved actuator for moving a member that produces a positive force at the termination of movement when no unintended object or person are the path of the member.
Another object of this invention is to provide an improved actuator for moving a member that produces a positive force at the termination of movement for insuring proper positioning of the member.
Another object of this invention is to provide an improved actuator for moving a member that may be applied to actuators of various designs as well as previously installed actuators.
Another object of this invention is to provide an improved actuator for moving a member that does not substantially reduce the speed of the actuator.
Another object of this invention is to provide an improved actuator for moving a member that does not substantially increase the cost of the actuator.
Another object of this invention is to provide an improved actuator for moving a member that provides a safer working environment for workers in proximity to the automated machine.
Another object of this invention is to provide an improved actuator for moving a member that reduces the damage to a tool and/or the workpiece in the event of misalignment of the tool relative to the workpiece.
The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed as being merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention with in the scope of the invention. Accordingly other objects in a full understanding of the invention may be had by referring to the summary of the invention, the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.